Car windows block most, but not all, harmful sunlight. It's the ultraviolet radiation (UV rays) in sunlight that causes sunburn. It's also one of the main causes of skin cancer.
You're more likely to develop skin cancer if you have fair skin that burns easily, lots of moles or freckles, red or fair hair, or light-coloured eyes.
There are two types of UV in sunlight and exposure to either increases your risk of developing skin cancer.
UVB
- absorbed by the top layer of your skin.
- directly associated with sunburn.
UVA
- penetrates deeper into your skin.
- reduces elasticity and causes premature ageing.
Avoid burning
- Wear sunscreen or cover up if you’re on a road trip in summer with windows or a sunroof open.
- If you burn easily and drive a lot then you should wear sunscreen or cover up even if you keep windows closed. Use the air-conditioning to keep you cool.
- If you're driving with the roof down wear a hat and sunscreen.
- Make sure that passengers, particularly children, are protected too.
- Carry a sun hat, long-sleeved clothing and sunscreen in case you break down. You may not be able to find somewhere safe to wait for help that's also shady.
- Choose a sunscreen that can protect against both UVA and UVB.
- Stay out of the sun around the middle of the day when it's at its strongest.
- Protect your children's more sensitive skin by using sunscreen and clothing. Consider fitting extra shading to car windows.
- Choose sunglasses that provide UV protection.
Do car windows block UV radiation?
UV levels inside your car will depend on the type of glass, your direction relative to the sun, and whether you've got the windows open or closed.- Clear side windows block virtually all UVB but only about a third of UVA radiation.
- Laminated glass – used in all windscreens as well as side windows in some cars – is better and can block all UVB and more than three quarters of UVA radiation.
How to choose sunscreen
The Sun Protection Factor (SPF) is mainly a measure of UVB protection. The higher the better. A separate star rating (one to five) tells you how much UVA protection it gives. It's best to choose a ‘broad spectrum’ sunscreen that can protect you against UVA and UVB.